Fluid amount in simulation
You need to set the Inflow Velocity. On its own (with no velocity) the Inflow only adds fluid to the domain within the Inflow volume if there is actually space to place it - ie, if the fluid has moved away to make space for some more fluid. Gravity does not act on the fluid in the Inflow and since you have no Inflow Velocity the liquid stays where it is and only those drops that break away from the surface tension will fall. Simply give it a velocity (eg, Z = -1) to allow it to flow away from the Inflow.